Utilizing Dedupulication Technology

1. Storage savings

This is the obvious reason that so many companies look to deduplication. The Virtual Tape Library (VTL) has been extremely effective at improving backup performance over straight disk. But, even with the benefit of compression, the storage costs add up when trying to retain weeks of backup data on disk for quicker recovery. Deduplication lets you keep much more data on hand while significantly reducing disk consumption.

Note: Don’t let the marketing spin of 50:1 or 30:1 deduplication ratios mislead you. Common storage savings ratios are between 8:1 and 10:1, or 87.5% and 90%. A 20:1 ratio is 95%. You still have to store every unique block once, so size your solution accordingly.

2. Replication bandwidth savings

Replicating backup data on virtual tape has been available for many years; however the bandwidth requirements can be cost prohibitive. Deduplication reduces the bandwidth requirements by 90% or more. The ability to move the data over IP instead of by truck results in many additional benefits:

• No physical tape or tape handling
• No need for tape encryption (no risk of lost tapes)
• Centralized physical tape operations, when necessary
• Tier 2 and Tier 3 systems have cost effective DR solutions

Note: Once the deduplication repository of unique blocks is seeded with a couple of full backups, you will see the average deduplication ratio for each tape begin to rise to 20:1 or more. Don’t confuse this with your overall repository ratio. However, the actual deduplication ratio on the tape directly impacts the replication bandwidth required. At a 20:1 ratio, you are talking about utilizing only five percent of the original bandwidth.

3. Improved IT productivity

The fact is that it takes people to manage the making of tape copies, ejecting them and shipping the physical tapes for offsite storage. But while these actions are necessary, they are not adding much value to your business. By using remote data replication instead of physical tape shipping, valuable IT staff time is freed up for more productive work.

4. Reduction of facility requirements

Replacing physical tape libraries with a large amount of disk arrays and servers helps solve some problems, but it continues to put a load on the power and cooling requirements of your facility. Deduplication reduces this footprint greatly, and some solutions can utilize more energy efficient technologies like MAID storage to reduce it even further.

5. Improved recovery times

Having the backup data online for recovery saves the time required to locate and mount the necessary physical tape. Backup data is accessed directly from disk resources without having to search sequentially through a tape. This is especially valuable when using techniques such as synthetic backups that disperse backup data across many tapes. For customers with TSM, the recovery time from a non-collocated Copy Pool at a DR site can be slow. If the Primary Pool is replicated completely using deduplication and replication, your recovery times improve.

Note: Make sure you test recovery when evaluating deduplication products. The ability to stream the data out of the deduplicated repository is rarely discussed by vendors, because few solutions scale well as needs grow. Restore time may be far slower than backup time.

Conclusion

The primary ROI factors for deduplication are reducing disk storage and replication bandwidth. These are the enabling factors for many of the other reasons enterprises look to deduplication. If you keep this in mind, you should be able to come up with some additional benefits within your environment.